With his heart set on a toddler, Garson, 45, was taken by surprise upon meeting Nathan during an adoption fair in Los Angeles.

"It's like a pet fair – as horrifying as you can imagine," he recalls. "It was really hard. The 16-year-old fat, ugly kid, who has probably been to 30 of these, knows he's not going to get adopted. Like everything, cute wins."

To that end, Garson was shocked that his son was still in the system. "I couldn't believe my kid was actually available for adoption," says the doting dad. "He's so cute and sweet."

With the father-son duo living together since February, Garson reveals that the boy is adjusting well. "He's going into third grade, plays baseball, goes to karate and has a posse of pals," he notes.

In addition to adapting to his new home, Nathan will also be exposed to his father's celebrity status. "I think he's going to be freaked out when we go to New York, where [the SATC cast] are like the Yankees," jokes Garson. "We can't walk 20 feet without being mobbed."

Taking advantage of his time in New York, Garson, who will resume his role as Sarah Jessica Parker's pal Stanford Blatch in SATC, will also begin filming his role on the new series White Collar.